Chile’s Atacama Desert is so dry that some spots see rain only once a decade. Salt turns the sandy soil inhospitable, and ultraviolet radiation scorches the surface. So little can survive there that scientists have wondered whether snippets of DNA found in the soil are just part of the desiccated skeletons of long-dead microbes or traces of hunkered-down but still living colonies.

Two newly discovered giant viruses have the most comprehensive toolkit for assembling proteins found in any known virus. In a host cell, the viruses have the enzymes needed to wrangle all 20 standard amino acids, the building blocks of life.

Researchers dubbed the viruses Tupanvirus deep ocean and Tupanvirus soda lake, combining the name of the indigenous South American god of thunder,...

AUSTIN, Texas — If alien microbes crash-land on Earth, they may get a warm welcome.

When people were asked how they would react to the discovery of extraterrestrial microbial life, they give generally positive responses, researchers reported at a news conference February 16 at the annual meeting of the American Association for the Advancement of Science.

Since long before it gained fame as a precise gene-editing tool, CRISPR has had another job defending bacteria against viral invaders. And it’s far from alone. Ten sets of bacterial genes have similar, newly discovered defense roles, researchers report online January 25 in Science.

The discovery “probably more than doubles the number of immune systems known in bacteria,” says Joseph...

[Scientists] produced in a test tube a totally artificial copy of a type of DNA virus.… The particular type of viral DNA (called Phi X174) the researchers made is an extremely simple molecule of only five or six genes. Their achievement, however, lays the foundation for eventual synthesis of more complex DNAs. — Science News, December 30, 1967

Viruses in bats may have mixed and matched genes to create the virus that gave rise to the deadly SARS outbreak in 2003, a new study suggests. And it could happen again. All of the ingredients needed to create a new SARS virus are found among viruses currently infecting horseshoe bats, researchers report November 30 in PLOS Pathogens.

Fungi may affect gut health in unexpected ways, new research suggests.

High-fat diets may alter relationships between bacteria and fungi in mice’s intestines, contributing to obesity, researchers report October 11 in mSphere. In independent work, researchers report that a fungus teams up with two types of bacteria to fuel gut inflammation in people with Crohn’s disease. That work was...